Answer:
It needs the spines for protection
Explanation:
The cactus would develop the spines as a form of protection to protect itself from being consumed and to survive longer.
The igneous rock will be weathered and formed into a sedimentary rock
Answer:
During pregnancy it is the eighth month I think. Sorry if it’s wrong.
Explanation:
Similar to the other types of muscle, smooth muscle contraction is caused by the sliding of myosin and actin filaments over each other. Calcium initiates contractions in a different way in a smooth muscle than in a skeletal muscle.
Smooth muscles use less energy to generate the given amount of force, can substain contractile force without fatigue & uses calcium from the sarcoplasic reticulum & extracellular space.